Field of the Invention
The present invention relates to a technique for measuring an optical characteristic of an object.
Description of the Related Art
Some objects have a surface that appears differently according to an illumination direction of a light source and an observation direction. This is because reflected light leading from light with which the surface of the object is irradiated has a different characteristic according to the illumination direction and the observation direction. Therefore, there is widely known a technique for measuring a reflection characteristic of such an object. Japanese Patent Application Laid-Open No. 2008-249521 discusses a method that measures reflected light at a plurality of angles. First, a measurement apparatus drives a light reception unit to scan within a predetermined region corresponding to a position of a light source, and identifies a position of specular reflected light where a received light amount is maximized. Then, the measurement apparatus determines a plurality of measurement positions based on the identified position of the specular reflected light, and measures the light while moving the light reception unit, thereby detecting a reflection characteristic of a measurement target.
However, according to the method discussed in Japanese Patent Application Laid-Open No. 2008-249521, a mechanism, such as a motor and an arm, is necessary to set the light reception unit at a plurality of positions, thereby leading to a complicated configuration.